The overall aim of this project is to develop a system for the continuous exposure of experimental animals to various levels of simulated urban air pollution for extended periods of time. The effects of air polluion on animals in which known respiratory and cardiovascular disease models have been experimentally produced or are present spontaneously in genetic strains will be studied in four chambers having the same environmental conditions (i.e., temperature, humidity, and light) but which differ in levels of known urban air pollutants (zero, typical, episodic, and exaggerated). Although the primary objective is to study the effects on pre-existing diseases, any adverse effects of air pollution on relatively healthy animals will also be assessed since control animals will be included for each disease model. A flexible system, developed by the engineering unit of this program project, is being used for long-term continuous exposure of populations of animals to complex mixtures of gaseous and particulate pollutants in controlled concentrations. Pre-selected levels of urban air pollution are being created by means of a programmed monitoring system with feedback control. In addition to maintenance of the system, continuing goals of the engineering team will be refinements in the pollution generating components (especially in the simulation of urban aerosols), monitoring techniques and data evaluation. The animal models to be tested include hamsters with enzyme-induced emphysema and rats with hypertension, atherosclerosis, anemia, and a combination of hypertension and atherosclerosis. Once effects on appropriate models have been observed and evaluated, the flexibility designed into the air pollution generation system will make it possible to explore the biological and chemical mechanisms whereby air pollution influences the evolution of disease processes.